We can use the normal distribution to make confidence interval estimates for the population proportion, p, when
A) np 5.
B) n(1 - p) 5.
C) p has a normal distribution.
D) both np 5 and n(1 - p) 5.

Question

We can use the normal distribution to make confidence interval estimates for the population proportion, p, when​
A) ​np > 5.
B) ​n(1 - p) > 5.
C) ​p has a normal distribution.
D) ​both np > 5 and n(1 - p) > 5.

Quizplus · Accepted Answer

The normal distribution can be used to make confidence interval estimates for the population proportion, p, when both np > 5 and n(1-p) > 5. This is known as the "success-failure" condition, which ensures that the sampling distribution of the sample proportion is approximately normal. If either np or n(1-p) is less than or equal to 5, then the distribution may not be normal and other methods for making confidence intervals should be used.

We Can Use the Normal Distribution to Make Confidence Interval